I don’t know what they added or subtracted from CO-03 in redistricting, but the district as it existed in 2020 gave President Trump 51.6% to Biden’s 46.1% (a 5.5% Trump win), whereas, as redrawn, it gave Trump 52.9% to Biden’s 44.7% (an 8.2% Trump win).
https://www.cpr.org/2021/09/03/colorado-redistricting-map-proposal/
The biggest change is to the 3rd congressional district. Currently, it forms a massive hook encompassing the entire Western Slope and Pueblo. But the new staff map transforms it into a southern and western district that only reaches as far north as I-70, including Mesa and Eagle counties, and then stretches east past Pueblo to include Crowley, Otero and Las Animas counties.
Not everyone is pleased with the map though
“Rural Colorado is the huge loser,” said Josh Penry, a Republican campaign operative who worked to pass the amendments that set up the new redistricting process. “I mean, rural Colorado got sliced and diced.”